/* -----------------------------------------------------------------------------
 * ParserException.java
 * -----------------------------------------------------------------------------
 *
 * Producer : com.parse2.aparse.Parser 2.0
 * Produced : Wed Jul 27 12:21:32 CDT 2011
 *
 * -----------------------------------------------------------------------------
 */

package gov.nist.syslog.rfc3164Parser;

import java.util.Stack;

/**
 * Signals that a parse failure has occurred.
 * Producer : com.parse2.aparse.Parser 2.0
 * Produced : Wed Jul 27 12:21:32 CDT 2011
 */

public class ParserException extends Exception {

    private static final long serialVersionUID = 1L;
    static final private String newline = System.getProperty("line.separator", "\n");
    private String reason;
    private String text60;
    private int index60;
    private Stack<String> ruleStack;

    /**
     * Creates a parser exception from the specified parse failure information.
     *
     * @param reason    A description of the parse failure.
     * @param text      The string of characters being parsed.
     * @param index     The index to the character at which the parse failure occurred.
     * @param ruleStack The ABNF rule stack at the point the parse failure occurred.
     */

    public ParserException(
            String reason,
            String text,
            int index,
            Stack<String> ruleStack) {
        this.reason = reason;
        this.ruleStack = ruleStack;

        int start = (index < 30) ? 0 : index - 30;
        int end = (text.length() < index + 30) ? text.length() : index + 30;
        text60 = text.substring(start, end).replaceAll("[^\\p{Print}]", " ");
        index60 = (index < 30) ? index : 30;
    }

    /**
     * Returns the description of the parse failure.
     *
     * @return The description of the parse failure.
     */

    public String getReason() {
        return reason;
    }

    /**
     * Returns a substring of the parsed string that encompasses the point
     * at which the parse failure occurred. The substring will be up to 60
     * characters in length unless the point of failure occurred within
     * 30 characters of the start or end of the parsed string.
     * {@link #getSubstringIndex} returns an index to the character within
     * this substring at which the parse failure occurred. This substring
     * may contain non-printable characters.
     *
     * @return The substring that encompasses the point of failure.
     */

    public String getSubstring() {
        return text60;
    }

    /**
     * Returns an index to the character within the substring returned by
     * {@link #getSubstring} at which the parse failure occurred.
     *
     * @return The index to the character within the substring returned
     * {@link #getSubstring} at which the parse failure occurred.
     */

    public int getSubstringIndex() {
        return index60;
    }

    /**
     * Returns the ABNF rule stack at the point the parse failure occurred.
     *
     * @return The ABNF rule stack.
     */

    public Stack<String> getRuleStack() {
        return ruleStack;
    }

    /**
     * Returns a message detailing the parse failure. The message detail
     * the reason for the failure and where the failure occurred.
     * <p>
     * <br><br>For example ...<br><br><code>
     * rule "Minutes" failed<br>
     * 15:75:47<br>
     * &nbsp;&nbsp;&nbsp;^<br>
     * rule stack:<br>
     * &nbsp;&nbsp;Clock<br>
     * &nbsp;&nbsp;Minutes</code><br>
     *
     * @return Details of the parse failure.
     */

    public String getMessage() {
        String marker = "                              ";

        StringBuffer buffer = new StringBuffer();
        buffer.append(reason + newline);
        buffer.append(text60 + newline);
        buffer.append(marker.substring(0, index60) + "^" + newline);

        if (!ruleStack.empty()) {
            buffer.append("rule stack:");

            for (String rule : ruleStack)
                buffer.append(newline + "  " + rule);
        }

        return buffer.toString();
    }
}

/* -----------------------------------------------------------------------------
 * eof
 * -----------------------------------------------------------------------------
 */